Multicylinder internal combustion engine

ABSTRACT

An internal combustion engine having two or more cylinders vertically disposed, one relative to the other or others, the fuel for the vertically disposed cylinders being supplied through a single main induction pipe, the conduit being in fluid communication with a horizontally divided cylinder induction conduit, a portion of the divided cylinder induction conduit being utilized for each of the plurality of cylinders for feeding fuel mixture thereto.

I United States Patent mi 3,592,1 73

|72] lnvenlor Dieter Frehe 2,227,247 l2/l940 Conover l23/73 A Macon, France 2,264,365 l2/l 94| Conover l23/73 A |211 Appl, No. 839.433 2,442,217 5/1948 smiihmm.. .Y Iza/73 A [22| Filed July 7,1969 2,7I7,584 9/1955 Upton l23/73 A [45] Patented July I3, 197| 3,020,707 2/1962 Post et :il4 i i l23/73 A {73} Assignee Wllter Gutbmd and Wolfgang Gutbrod, 3,132,635 5/l964 Heidner l23/73 A Gutbmd-Werke GmbH 3,170,449 2/l965 Goggi,... IZB/73 A Bublngenigghnhlngerhof. Germany 3,308,797 3/1967 Buyaiti i 123/52 M (32| Priority July 21, 1968 3,395,679 8/1968 Christner 123/73 A [33] Germany 3,472,211 l0/l969 Meininger l23/74 I3 l] P 17 sl 7463 Primary Examiner-Wendell E. Burns Auorriey-Harnes s, Dickey and Pierce [54] MULTICYLINDER INTERNAL COMBUSTION ENGINE 6 Claims, 3 Drawing Figs.

(52] U.S. Cl- ,i 123/52 M, 12B/59, l23/73 l5ll lllcl F02|J 75/18, ABSTRACT: An internal combustion engine having two or F02b 33/04, F02b 75/20 more cylinders vertically disposed, one relative to the other or [50] Field nl Search 123152 M, others, the fuel for the vertically disposed cylinders being sup- 59 73 A 74. 74 A plied through a single main induction pipe, the conduit being [56] Re Cm in fluid communication with a horizontally divided cylinder inl,4l8,l00 5/1922 Simmons UNITED STATES PATENTS duction conduit, a portion of the divided cylinder induction conduit being utilized for each of the plurality of cylinders for feeding fuel mixture thereto.

PATENTEDJuLlafsl Fig. 2

/n ven lar.'

MULTICYLINDER INTERNAL COMBUSTION ENGINE BACKGROUND AND SUMMARY OF THE DEVELOPMENT This invention relates generally to a multicylinder fuel burning engine, and more particularly to a fuel burning engine having at least two superposed or vertically aligned cylinders, each of the cylinders being supplied with an air-fuel or airfuel-lubricating oil mixture through a common main induction pipe and successively through branched-off portions of a cylinder fuel induction conduit, the branchedoff portions being horizontally positioned, one relative to the other, relative to gravity.

One important requirement in the case of multicylinder fuel-burning engines is the qualitative distribution of the fuel mixture to the cylinders, to the extent that the proportion of fuel, and lubricating oil in the case of two cycle internal combustion engines, shall be equal in the volume of air inducted into all ofthe cylinders. ln this situation, the engine is more smooth running, the life of the engine is increased and an opA timum use of the consumed fuel is made.

Difficulties, with regard to the equal qualitative inducted mixture for each individual cylinder, have arisen in the case of fuel burning engines having a plurality of superposed or generally vertically aligned cylinders, the cylinders being connected to a common main induction pipe. Under these cir cumstances, an undesirable condition is created wherein the upper cylinder is charged with a mixture which is relatively thin as compared to the lower cylinder. Thus, the upper cylinder runs hot due to the lean mixture and the lower cylinder rapidly collects deposits within the cylinder to decrease the efficiency thereof, ln these engines, the carbure tor is connected to ont.l end ofthe pipe while individual induction pipes having generally horizontally directed partitions or vertically directed branch pipes are connected to the individual cylinders.

The reason for this condition has been found to be due to the force of gravity acting on the charged fuelA ln this situation, wherein a cylinder induction pipe is disposed one above the other, the fuel has a tendency to fall to the lower cylinder thus causing a deposit of fuel and lubricating oils in the individual cylinder pipe walls. During subsequent charges of fuel into the cylinder this excess of fuel and lubricant is picked up by the fuel vapor How to greatly enrich the lower cylinder. Due to the action of gravity, the excess fuel in the lower cylinder is derived from the fuel which would normally be applied to the upper cylinder, the upper cylinder thus being fuel starved or charged with a thinner mixture than would normally be required. Thus, the upper cylinder would run hotter than normal due to the leaner mixture.

Certain prior systems for eliminating this undesirable feature in vertically stacked cylinders have been provided, but have certain drawbacks. For example, certain systems employ complicated diaphragm systems beyond the carburetor, certain other systems dispose the carburetor eccentrically, and other systems employ drip holes in the region of the lower cylinder. lt is seen that these solutions to the problem are either expensive to construct or the systems do less than a perv fect job.

With the system of the present invention, these conditions are alleviated due to the creation of an induction system for a fuel burning engine in which the cylinders are provided with generally uniform flow conditions and qualitatively equal induction mixtures are obtained for each of the cylinders. The features of the present invention solve the aforementioned problems by providing an individual cylinder induction system, the intakes to each of the vertically stacked cylinders being generally horizontally aligned and having a configuration to enhance the possibility that the cylinders will be supplied with an equal charge of fuel. Particularly, an individual branch is provided for the individual cylinders and connected to the main induction pipe, the intake pipe having a vertical separating wall in the case of two cylinders, or having a plurality of separating walls in the case of more than two cylin ders to divide the fuel charge. Further, the adjacent and horizontally aligned individual cylinder induction conduits connected to the main induction pipe are curved in such a way that the cylinder end openings are situated in a common transverse plane through each ofthe cylinders.

Through the use of the horizontally aligned arrangement of inlet openings of the individual cylinder induction conduits, equal flow conditions are obtained for cach of the individual cylinder induction conduits over their cross section. Thus` there is obtained equal qualitative and quantitative charging of the individual cylinders with fuel and lubricating oil due to the vertical dividing up ofthe main opening ofthe main induction pipe into the generally equal openings of the individual cylinder induction pipes and thc general horizontal alignment of the input portions of thc individual cylinder induction pipes. Thus, the unequal vertical distribution of the fuel and lubricating oil inducted flow can no longer divide differently, depending on the vertical disposition ofthe individual cylinder pipe.

Accordingly, it is one object ofthe present invention to provide an improved fuel induction system for an internal com bustion engine4 lt is another object of the present invention to provide an improved fuel induction system for use with an internal com bastion engine having generally vertically aligned cylinders.

lt is still a further object of the present invention to provide an improved input induction system for the individual cylinders of an internal combustion engine wherein the individual cylinder conduits equally divide up the fuel charge from the main induction pipe.

It is still a further object of the present invention to provide an improved individual cylinder induction system so that the output of the individual cylinder induction conduit is generally positioned at approximately thc same point iii the cylinder as the other exit positions of the other individual cylinder induction conduits in their respective cylinders.

lt is still another object of the present invention to provide an improved system for eq ualizing the fuel charge to vertically disposed individual cylinders of an internal combustion en` gine.

lt is still a further object of the present invention to provide an improved individual cylinder induction system wherein the inlet for the various intake induction systems are divided by a vertical partition so that the individual portions of the induction system are horizontally aligned Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims and the accompanying drawing in whichi FIG. l illustrates a partial side view of an air-cooled, twocylinder, fuelburning engine having two vertically, super posed cylinders:

FIG. 2 is a section of the engine of FlG. l, taken along thc line ll-ll thereof, and

FIGA 3 is a partial perspective view of the section of FIG. 2 illustrating the division and the course of the cylinder indue tion channels of the system ofthe present invention.

The invention has been rcpresentatively illustrated in con` nection with a two-cylinder internal combustion engine l0 However, it is to be understood that the invention is equally applicable to engines having more than two cylinders, radial engines and other engines having fuel feeding problems similar to those described above. Referring more particularly to the drawing, the engine l0 includes a first cylinder l and a second cylinder 2, the second cylinder 2 being vertically superposed on the first cylinder l. The engine l0 is illustrated as being of the aircooled type and includes a plurality of heat radiating fins integrally cast with the main body portion of the engine,

The cylinders l and 2 are provided with a fuel-air mixture from a carburetor device 8 through a main induction pipe 7 to the inlet portion of a common, individual cylinder neck portion 13 of an intake conduit assembly 3. The carburetor 8 may be of a conventional type and is adapted to provide a mixture of fuel and air in the case of four'cycle engines and fuel, air and lubricating oil in the case of two-cycle enginesY The main induction pipe 7 is provided with a flange portion I4 which is adapted to be bolted to thc inlet part 13 of the individual cylinder conduit assembly 3, For this purpose, a pair of threaded holes I6 (FIG. 3) are provided.

As was stated above, in the prior systems, the individual cylinder induction system included a main induction pipe which was connected to a Y-section induction pipe, the fuel mixture being caused to divide for providing a fuel charge into the upper and lower cylinders. ln this situation, the divided fuel had a tendency to favor the lower cylinder and provide the lower cylinder with an extra charge of fuel, with the attenY dant difficulties noted above. ln accordance with the system of the present invention, the inlet section of the individual cylinder pipe 3 is provided with a divider element 6 which is generally vertically disposed to divide the inlet chamber of the pipe 3 into two equal sections 4a, 5u. The two sections 4u, 5u are of generally equal cross section to preclude the possibility ofthe fuel charge favoring one sidi: or the other of partition 6. The inlet openings 4u, 5a provide a fuel charge for the respective induction channels 4, 5 which are cast into the body portion ofthe engine l0. The cylinder induction channels 4, 5 are provided to introduce fuel from the main induction pipe 7, through the individual induction channels 4 and 5, to the in terior portion ofthe cylinders l and 2.

lt is to be noted that the cylinder induction channels 4 and 5 are curved, as best illustrated in FIG. 3, in an area inter4v mediate the input and output sections ofthe individual induction channels. The surfaces ofthe channels are curved in such a way that the output cylinder openings 4b and 5b are situated in a common plane which is generally vertical and transverse through the cylinders l and 2. ln this way the fuel enters the cylinder at approximately the same point for cach cylinder to further enhance the equal Characteristics of the fuel charge: and its combustion for each cylinder.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

lclaim;

l. A fuel intake system for supplying a fuel charge mixture to at least one combustion chamber of an internal combustion engine, the intake system being under the influence of the force of gravity to affect the mixture of the charge duc to the force of gravity, the intake system comprising a common intake conduit, individual conduit means in tluid communica tion with said common conduit and downstream of said common conduit relative to the direction of flow of the fuel charge, said individual conduit means having portions arranged to direct the fuel charge upwardly and downwardly relative to the direction ofthe force of gravity, and apportioning means positioned between said individual conduit means portions and at least a portion of said common conduit for ap portioning, free of the effects of the force of gravity, the fuel charge to said individual conduit means.

2. The improvement of claim l wherein said apportioning means has an intake opening, and divider means positioned in said intake opening and extending in a direction parallel to a liiic along the force of gravity.

3. The improvement ot" claim 2 wherein the internal com bustion engine includes a plurality of combustion chambers which are superposcd and said divider means is vertically disposed and generally parallel to a line through the superY posed chambers.

4. The improvement of claim 3 wherein said intake opening divider means l'orins two chambers in sidc-by-side relationshiukone relative tothe other. l l

. The improvement ol claim 4 wherein said individual con duit means includes at least two individual conduit portions having outlet openings into at least one combustion chamber, the conduits being curved such that the outlet openings are superposed vertically.

6. The improvement of claim S wherein said outlets of said individual conduit portions for each superposed combustion chamber ari.- conncctcd io the combustion chamber in the same relativi: position. 

1. A fuel intake system for supplying a fuel charge mixture to at least one combustion chamber of an internal combustion engine, the intake system being under the influence of the force of gravity to affect the mixture of the charge due to the force of gravity, the intake system comprising a common intake conduit, individual conduit means in fluid communication with said common conduit and downstream of said common conduit relative to the direction of flow of the fuel charge, said individual conduit means having portions arranged to direct the fuel charge upwardly and downwardly relative to the direction of the force of gravity, and apportioning means positioned between said individual conduit means portions and at least a portion of said common conduit for apportioning, free of the effects of the force of gravity, the fuel charge to said individual conduit means.
 2. The improvement of claim 1 wherein said apportioning means has an intake opening, and divider means positioned in said intake opening and extending in a direction parallel to a line along the force of gravity.
 3. The improvement of claim 2 wherein the internal combustion engine includes a plurality of combustion chambers which are superposed and said divider means is vertically disposed and generally parallel to a line through the superposed chambers.
 4. The improvement of claim 3 wherein said intake opening divider means forms two chambers in side-by-side relationship, one relative to the other.
 5. The improvement of claim 4 wherein said individual conduit means includes at least two individual conduit portions having outlet openings into at least one combustion chamber, the conduits being curved such that the outlet openings are superposed vertically.
 6. The improvement of claim 5 wherein said outlets of said individual conduit portions for each superposed combustion chamber are connected to the combustion chamber in the same relative position. 